I couldn't find a license plate mod that was similar to the current New York plates, but still fit with GTA IV, so I created my own :D
It has "Liberty" written on top portion, "Happiness" written on bottom portion, and "ABC 2345" for the alphanumeric call letters. I know the letters are kind of stupid, but I wanted them to be sort of generic, since all cars had the same plates, so I just kept them that way :) This is one of my first GTA IV mods, so keep that in mind lol

The third screenshot shows how the mod looks ingame best, and the last image is the one I created before putting it into GTA IV.

Tools Used:
Adobe Photoshop CS6
Nvidia DDS Plugin
SSBump Generator
Credits:
tartilc